1.1: aq. HCl; acetone / 0.5 h / 20 °C 2.1: acetic acid; pyrrolidine / benzene / 2 h / Heating 3.1: sodium hydride / tetrahydrofuran / 0.58 h 3.2: tetrahydrofuran / 13.5 h 4.1: aq. HCl / 60 h / Heating 5.1: thionyl chloride / 17.5 h 6.1: urea; NaOEt / ethanol / 17 h / Heating 7.1: borane-tetrahydrofuran / tetrahydrofuran / 19 h / Heating View Scheme

1.1: Mg / tetrahydrofuran / 1 h / Heating 1.2: tetrahydrofuran / 2 h / Heating 2.1: aq. HCl; acetone / 0.5 h / 20 °C 3.1: acetic acid; pyrrolidine / benzene / 2 h / Heating 4.1: sodium hydride / tetrahydrofuran / 0.58 h 4.2: tetrahydrofuran / 13.5 h 5.1: aq. HCl / 60 h / Heating 6.1: thionyl chloride / 17.5 h 7.1: urea; NaOEt / ethanol / 17 h / Heating 8.1: borane-tetrahydrofuran / tetrahydrofuran / 19 h / Heating View Scheme

1.1: sodium hydride / tetrahydrofuran / 0.58 h 1.2: tetrahydrofuran / 13.5 h 2.1: aq. HCl / 60 h / Heating 3.1: thionyl chloride / 17.5 h 4.1: urea; NaOEt / ethanol / 17 h / Heating 5.1: borane-tetrahydrofuran / tetrahydrofuran / 19 h / Heating View Scheme

1: thionyl chloride / 17.5 h 2: urea; NaOEt / ethanol / 17 h / Heating 3: borane-tetrahydrofuran / tetrahydrofuran / 19 h / Heating View Scheme

1.1: acetic acid; pyrrolidine / benzene / 2 h / Heating 2.1: sodium hydride / tetrahydrofuran / 0.58 h 2.2: tetrahydrofuran / 13.5 h 3.1: aq. HCl / 60 h / Heating 4.1: thionyl chloride / 17.5 h 5.1: urea; NaOEt / ethanol / 17 h / Heating 6.1: borane-tetrahydrofuran / tetrahydrofuran / 19 h / Heating View Scheme

1.1: p-toluenesulfonic acid monohydrate / benzene / 3 h / Heating 2.1: Mg / tetrahydrofuran / 1 h / Heating 2.2: tetrahydrofuran / 2 h / Heating 3.1: aq. HCl; acetone / 0.5 h / 20 °C 4.1: acetic acid; pyrrolidine / benzene / 2 h / Heating 5.1: sodium hydride / tetrahydrofuran / 0.58 h 5.2: tetrahydrofuran / 13.5 h 6.1: aq. HCl / 60 h / Heating 7.1: thionyl chloride / 17.5 h 8.1: urea; NaOEt / ethanol / 17 h / Heating 9.1: borane-tetrahydrofuran / tetrahydrofuran / 19 h / Heating View Scheme

trifluorormethanesulfonic acid T=25°C;